JPH04290563A - Centrifugal machine - Google Patents

Abstract

PURPOSE:To offer a centrifugal machine excellent in operability by eliminating play of a connection part of a rotor with a rotating shaft in centrifugal machine and by removing abnormal vibration or sticking phenomena of the rotor with the rotating shaft. CONSTITUTION:The holding component which is able to shift to the radius direction is provided on the rotating shaft and the coupling hole 3 of the rotor 4 in which the rotating shaft 1 is inserted is held at least with three point by the holding component 2.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a centrifugal machine with a rotor attached to a rotating shaft for centrifugal separation.

0002

2. Description of the Related Art FIG. 2 shows a rotor holding mechanism in a conventional unbalance compatible centrifuge and high speed rotation compatible centrifuge. Ideally, the radius r1 of the rotating shaft 1 that rotates a rotor (not shown) and the radius r3 of the coupling hole 3 should be r1=r3. However, as is clear from the figure, a small gap is created between the rotating shaft 1 and the rotor holding surface inside the coupling hole 3 due to limitations in processing accuracy. That is, actually r1≈r3. Therefore, a radially movable holding member 2 is attached to the upper end of the rotating shaft 1 having a tapered surface, and a coupling hole 3
It is inserted into the rotor to hold the rotor and rotate it at high speed. At this time, there were only two holding positions: a contact point D between the rotating shaft 1 and the holding surface in the coupling hole 3, and a contact point E between the convex portion of the holding member 2 and the holding surface in the coupling hole 3.

0003

[Problems to be Solved by the Invention] Among the conventional centrifuges mentioned above, the amount of unbalance of the rotor increases in unbalance compatible centrifuges, and in high-speed centrifuges, abnormal vibration occurs due to high speed rotation. Or, a gulp phenomenon may occur between the rotating shaft 1 and the coupling hole 3. These problems are caused by the play between the rotating shaft 1 and the coupling hole 3 caused by the two-point support described above. Although problems such as vibration as described above can be eliminated by fixing the rotor to the rotating shaft 1 using screws or the like, the rotor installation and removal becomes complicated and operability deteriorates.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a centrifugal machine that eliminates abnormal vibrations between the rotating shaft and the coupling hole and has good operability.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides for attaching a radially movable holding member to the upper end of the rotating shaft into which a coupling hole provided at the bottom of the rotor is inserted; The radius of curvature of the holding member is greater than or equal to the radius of the coupling hole.

[0006]

[Operation] In the centrifuge configured as described above, the rotating shaft and the coupling hole are in contact at at least three points, so the rotor is securely held and abnormal vibrations are suppressed. can act.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained below with reference to the drawings. Figure 4
FIG. 2 is a longitudinal cross-sectional view showing the structure of a centrifuge drive section. Rotating room 6
A rotor 4 housed therein is provided with a coupling hole 3 for coupling with the rotating shaft 1. A drive device 5 is provided below the rotation chamber 6, and a rotation shaft 1 extending upward from the drive device 5 is inserted into the coupling hole 3 to couple the rotor 4 and the rotation shaft 1, and the The rotational drive of the device 5 is transmitted to the rotor 4.

FIG. 3 is an enlarged longitudinal cross-sectional view of the connecting portion of the rotating shaft 1 and rotor 4 shown in FIG. A groove is provided at the upper end of the rotating shaft 1 into which the coupling hole 3 is inserted, and a holding member 2 is attached to the groove. The holding member 2 and the rotating shaft 1 are connected by a spring 5, and the holding member 2 presses against the coupling hole 3 in the radial direction.

Furthermore, the radius of curvature r2 of the holding member 2 is
It is larger than the radius r1 of the rotating shaft 1. That is, r1<r2. Therefore, the holding member 2 pressed in the radial direction by the spring 5 comes into contact with the coupling hole 3 at two points B and C, and the rotating shaft 1 is held at three points A, B, and C. Become.

When the weight of the holding member 2 is 4.8 g and the radius of rotation at the center of gravity is approximately 8 mm, the rotation speed is set to 700 per minute.
At 00 rotations, the load applied by the centrifugal force on the holding member 2 reaches 210 kg, so in the case of three-point holding without any play, the pressing force of the holding member 2 against the coupling hole 3 is even more reliable. This will make the holding even stronger.

[0011]

[Effects of the Invention] As detailed above, according to the present invention,
Since the rotating shaft and the rotor coupling hole are supported at at least three points, it is possible to eliminate play at the joint between the rotating shaft and the rotor coupling hole, which prevents abnormal vibrations and interference between the rotor and the rotating shaft. Since the sticking phenomenon can be prevented, the rotor can be held securely. Furthermore, since the structure does not require screws or the like, it is possible to provide a centrifuge with excellent operability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view taken along the line OO' in FIG. 3, showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a conventional rotor holding state.

FIG. 3 is a longitudinal cross-sectional view showing a joint between a rotating shaft and a rotor according to an embodiment of the present invention.

FIG. 4 is a longitudinal cross-sectional view showing the structure of the drive part of the centrifuge.

[Explanation of symbols]

1 is a rotating shaft, 2 is a holding member, 3 is a coupling hole, 4 is a rotor, and 5 is a spring.

Claims (1)

[Claims] 1. A centrifuge in which the rotor is rotated by inserting the upper end of the rotating shaft into a coupling hole provided at the bottom of the rotor, wherein the upper end of the rotating shaft inserted into the coupling hole has a radius. 1. A centrifuge, characterized in that a holding member movable in the direction is attached, and the holding member has a radius of curvature greater than or equal to the radius of the coupling hole.